According to a previously proposed multi printing drum stencil printing device which is disclosed in Japanese patent publication for opposition purpose (kokoku) No. 04-15739, a plurality of printing drums are mounted on a planetary disk (printing drum supporting member) which is adapted to be rotated around its center of rotation, with each printing drum adapted to be rotated around a central axial line thereof, and each of the printing drums is selectively brought to a stencil printing position opposing a press roller by the indexing action of the planetary disk.
According to this multi printing drum stencil printing device, by using a printing ink of a different color for each of the printing drums, a stencil printing of a desired color, a multi color stencil printing or a full color stencil printing using the colors of cyan, magenta, yellow and black can be accomplished by the indexing action of the planetary disk without involving the need for replacing the printing drums.
According to such a conventional multi printing drum stencil printing device, the indexing movement of the planetary disk and the rotative actuation of the printing drums were effected by separate electric motors, and the number of necessary electric motors was equal to the number of the printing drums plus one. Therefore, five electric motors were necessary when there were four printing drums for full color printing. This is highly detrimental to the compact and light weight design of the stencil printing device, and also contributes to the increase in the cost.
Furthermore, these motors were required to be individually controlled, and not only the mechanical structure but also the control system tended to be highly complex. Also, the efforts and cost required for maintenance were also substantial.